Abstract: A process for removing carbon dioxide from a fluid comprises the steps of: (a) treating the fluid by bringing it into countercurrent contact with a liquid absorbent in a first absorption zone and thereafter in a second absorption zone to absorb at least part of the carbon dioxide contained in the fluid into the absorbent; (b) depressurizing the loaded absorbent to release a first stream of carbon dioxide and yield a partially regenerated absorbent; (c) recycling a first stream of the partially regenerated absorbent into the first absorption zone; (d) heating a second stream of the partially regenerated absorbent to release a second stream of carbon dioxide and yield a regenerated absorbent; (e) recycling the regenerated absorbent into the second absorption zone; (f) condensing water vapor entrained in the second stream of carbon dioxide by cooling the second stream of carbon dioxide and transferring at least part of the heat recovered to the partially regenerated absorbent by indirect heat exchange.

Abstract: A process for removing carbon dioxide from a fluid comprises the steps of: (a) treating the fluid by bringing it into countercurrent contact with a liquid absorbent in a first absorption zone and thereafter in a second absorption zone to absorb at least part of the carbon dioxide contained in the fluid into the absorbent; (b) depressurizing the loaded absorbent to release a first stream of carbon dioxide and yield a partially regenerated absorbent; (c) recycling a first stream of the partially regenerated absorbent into the first absorption zone; (d) heating a second stream of the partially regenerated absorbent to release a second stream of carbon dioxide and yield a regenerated absorbent; (e) recycling the regenerated absorbent into the second absorption zone; (f) condensing water vapor entrained in the second stream of carbon dioxide by cooling the second stream of carbon dioxide and transferring at least part of the heat recovered to the partially regenerated absorbent by indirect heat exchange.

Abstract: An absorption medium for removing acid gases from a fluid stream comprises an aqueous solution of A) at least one cyclic amine compound having solely tertiary amine groups and/or sterically hindered secondary amine groups and B) at least one cyclic amine compound having at least one sterically unhindered secondary amine group. The absorption medium comprises, e.g., an aqueous solution of A) 1-hydroxyethylpiperidine and/or triethylenediamine and B) piperazine. The absorption medium is particularly suitable for separating off carbon dioxide from flue gases and satisfies the following criteria: (i) sufficient capacity at low CO2 partial pressures; (ii) sufficiently rapid absorption rate at low CO2 partial pressures; (iii) stability toward oxygen; (iv) low vapor pressure for reducing solvent losses; and (v) low energy requirement for regeneration of the absorption medium.

Abstract: An absorption medium for removing acid gases from a fluid stream comprises an aqueous solution of A) at least one cyclic amine compound having solely tertiary amine groups and/or sterically hindered secondary amine groups and B) at least one cyclic amine compound having at least one sterically unhindered secondary amine group. The absorption medium comprises, e.g., an aqueous solution of A) 1-hydroxyethylpiperidine and/or triethylenediamine and B) piperazine. The absorption medium is particularly suitable for separating off carbon dioxide from flue gases and satisfies the following criteria: (i) sufficient capacity at low CO2 partial pressures; (ii) sufficiently rapid absorption rate at low CO2 partial pressures; (iii) stability toward oxygen; (iv) low vapor pressure for reducing solvent losses; and (v) low energy requirement for regeneration of the absorption medium.

Abstract: A method for removing acid gases from a fluid stream comprises a) treating the fluid stream in an absorption zone with an absorption medium which comprises an aqueous solution of at least one amine, conducting the treated fluid stream through at least two scrubbing zones and treating it with a non-acidic aqueous phase in order to transfer entrained amine and/or entrained amine decomposition products at least in part to the aqueous phase, wherein aqueous phase is recycled via at least one scrubbing zone and aqueous phase is conducted through at least one scrubbing zone without recycling. The method permits efficient retention of amines from the treated fluid streams.

Abstract: A process for removing acid gases from a water vapour-containing fluid stream comprises a) providing an absorption liquid which is incompletely miscible with water; b) treating the fluid stream in an absorption zone with the absorption liquid to obtain an acid gas-depleted treated fluid stream and an acid gas-loaded absorption liquid; c) directing the treated fluid stream to a rehydration zone and treating the fluid stream with an aqueous liquid to volatilize at least part of the aqueous liquid; d) regenerating the loaded absorption liquid to expel the acid gases at least in part and obtain a regenerated absorption liquid, and directing the regenerated absorption liquid to step b); and e) separating, from the absorption liquid, an aqueous liquid that has condensed in the absorption zone, and directing the aqueous liquid to step c). The process allows for an efficient removal of water accumulated in the absorption liquid system.

Abstract: A process for removing acid gases from a fluid stream in which a) the fluid stream is treated with an absorption liquid which comprises at least one amine, a stripping aid, and water, wherein the stripping aid is selected from water-miscible liquids, the boiling temperature of which at atmospheric pressure is lower than that of water, b) the treated fluid stream is treated with a liquid aqueous phase in order to convert entrained stripping aid at least in part to the aqueous phase, c) the loaded aqueous phase is heated in order to expel the stripping aid at least in part, and d) the regenerated aqueous phase is cooled and at least in part recycled to step b). The stripping aid promotes the regeneration of the absorbent by stripping. Emissions of the stripping aid via the treated fluid stream are avoided by the treated fluid stream being scrubbed with a liquid aqueous phase.

Abstract: An absorption medium for removing acid gases from a fluid stream comprises an aqueous solution (A) of an alkali metal salt of an N,N-di-C1-C4-alkylaminocarboxylic acid and (B) N-hydroxyethylpiperazine. The absorption medium has a low vapor pressure and an increased resistance to oxygen. Preferred fluid streams are combustion exhaust gases or biogas.

Abstract: A process for removing carbon dioxide from a fluid flow, wherein a) the fluid flow is brought into contact with an absorption agent which contains a solution of ammonia and at least one amino carboxylic acid and/or amino sulfonic acid, a charged absorption agent being obtained, and b) the charged absorption agent is regenerated while releasing carbon dioxide. The additional use of the amino carboxylic acid and/or amino sulfonic acid increases the circulation absorption capacity of the absorption agent.

Abstract: Absorption medium for acid gases comprising an oligoamine (A) of the general formula (I) and a piperazine derivative (B) of the general formula (II) in which the weight ratio of oligoamine (A) to the piperazine derivative (B) is 0.2 to 25, and also process for removing acid gases from a gas stream by contacting the gas stream at a pressure of 0.05 to 10 MPa abs with an aqueous solution of said absorption medium which is brought to and maintained at a temperature of 20 to 80° C.

Abstract: Absorption medium for acid gases comprising an oligoamine (A) of the general formula (I) and a primary or secondary alkanolamine (B) of the general formula (II) in which the weight ratio of oligoamine (A) to the primary or secondary alkanolamine (B) is 0.2 to 4, and also the process for removing acid gases from a gas stream by contacting the gas stream at a pressure of 0.05 to 10 MPa abs with an aqueous solution brought to and maintained at a temperature of 20 to 80° C. of said absorption medium.

Abstract: A method for removing acid gases from a fluid stream comprises a) treating the fluid stream in an absorption zone with an absorption medium which comprises an aqueous solution of at least one amine, conducting the treated fluid stream through at least two scrubbing zones and treating it with a non-acidic aqueous phase in order to transfer entrained amine and/or entrained amine decomposition products at least in part to the aqueous phase, wherein aqueous phase is recycled via at least one scrubbing zone and aqueous phase is conducted through at least one scrubbing zone without recycling. The method permits efficient retention of amines from the treated fluid streams.

Abstract: An absorption medium for removing acid gases from a fluid stream comprises an aqueous solution of a) of at least one metal salt of an aminocarboxylic acid, and b) of at least one acid promoter, wherein the molar ratio of b) to a) is in the range from 0.0005 to 1.0. The acid promoter is selected from mineral acids, carboxylic acids, sulfonic acids, organic phosphonic acids and partial esters thereof. The absorption medium, compared with absorption media based on amino acid salts, has a reduced regeneration energy requirement without significantly reducing the absorption capacity of the solution for acid gases. In a process for removing acid gases from the fluid stream, the fluid stream is brought into contact with the absorption medium.

Abstract: An absorption medium for the removal of acid gases from a fluid stream comprises an aqueous solution a) of at least one amine and b) at least one phosphonic acid, wherein the molar ratio of b) to a) is in the range from 0.0005 to 1.0. The phosphonic acid is, e.g., 1-hydroxyethane-1,1-diphosphonic acid. The absorption medium exhibits a reduced regeneration energy requirement compared with absorption media based on amines or amine/promoter combinations, without significantly decreasing the absorption capacity of the solution for acid gases.

Abstract: A process for removing carbon dioxide from a fluid comprises the steps of: (a) treating the fluid by bringing it into countercurrent contact with a liquid absorbent in a first absorption zone and thereafter in a second absorption zone to absorb at least part of the carbon dioxide contained in the fluid into the absorbent; (b) depressurizing the loaded absorbent to release a first stream of carbon dioxide and yield a partially regenerated absorbent; (c) recycling a first stream of the partially regenerated absorbent into the first absorption zone; (d) heating a second stream of the partially regenerated absorbent to release a second stream of carbon dioxide and yield a regenerated absorbent; (e) recycling the regenerated absorbent into the second absorption zone; (f) condensing water vapour entrained in the second stream of carbon dioxide by cooling the second stream of carbon dioxide and transferring at least part of the heat recovered to the partially regenerated absorbent by indirect heat exchange.

Abstract: The invention relates to a process for preparing free-flowing, pulverulent alkoxycarbonylaminotriazine from an alkanolic reaction mixture which is obtained in the preparation of alkoxycarbonylaminotriazines and comprises at least one alkoxycarbonylaminotriazine, at least one cyclic and/or acyclic carbonic ester, at least one C1-C13-alkanol which optionally comprises one or two oxygen atoms in the form of ether bonds and is optionally substituted by C1-C4-alkyl and/or hydroxyl, and also at least one alkali metal or alkaline earth metal alkoxide, with or without melamine and with or without catalyst, by atomizing and drying the reaction mixture in a spray drier.

Abstract: Absorption medium for acid gases comprising an oligoamine (A) of the general formula (I) and a primary or secondary alkanolamine (B) of the general formula (II) in which the weight ratio of oligoamine (A) to the primary or secondary alkanolamine (B) is 0.2 to 4, and also the process for removing acid gases from a gas stream by contacting the gas stream at a pressure of 0.05 to 10 MPa abs with an aqueous solution brought to and maintained at a temperature of 20 to 80° C. of said absorption medium.

Abstract: Absorption medium for acid gases comprising an oligoamine (A) of the general formula (I) and a piperazine derivative (B) of the general formula (II) in which the weight ratio of oligoamine (A) to the piperazine derivative (B) is 0.2 to 25, and also process for removing acid gases from a gas stream by contacting the gas stream at a pressure of 0.05 to 10 MPa abs with an aqueous solution of said absorption medium which is brought to and maintained at a temperature of 20 to 80° C.

Abstract: An absorption medium for removing acid gases from a fluid stream comprises an aqueous solution (A) of an alkali metal salt of an N,N-di-C1-C4-alkylaminocarboxylic acid and (B) N-hydroxyethylpiperazine. The absorption medium has a low vapor pressure and an increased resistance to oxygen. Preferred fluid streams are combustion exhaust gases or biogas.

Abstract: A process for removing acid gases from a fluid stream in which a) the fluid stream is treated with an absorption liquid which comprises at least one amine, a stripping aid, and water, wherein the stripping aid is selected from water-miscible liquids, the boiling temperature of which at atmospheric pressure is lower than that of water, b) the treated fluid stream is treated with a liquid aqueous phase in order to convert entrained stripping aid at least in part to the aqueous phase, c) the loaded aqueous phase is heated in order to expel the stripping aid at least in part, and d) the regenerated aqueous phase is cooled and at least in part recycled to step b). The stripping aid promotes the regeneration of the absorbent by stripping. Emissions of the stripping aid via the treated fluid stream are avoided by the treated fluid stream being scrubbed with a liquid aqueous phase.